Atrial Fibrillation in Genotyped Dilated Cardiomyopathy: Epidemiology, Risk Factors, and Outcomes: Insights From the SHaRe Registry

BACKGROUND: – Atrial fibrillation (AF) is the most common arrhythmia in dilated cardiomyopathy (DCM) and is associated with adverse outcomes. However, the genetic determinants of AF risk and its prognostic significance across genotyped DCM subtypes remain unknown. METHODS: – In this observational cohort study, we analyzed 3117 genotyped patients with DCM from the SHaRe (Sarcomeric Human Cardiomyopathy Registry). AF prevalence, incidence, and clinical characteristics were assessed by genotype. Patients were classified as genotype-positive [G(+)] if they had a pathogenic or likely pathogenic variant in a DCM-associated gene, and genotype-negative [G(−)] if genetic testing was negative. Factors associated with incident AF were evaluated using Cox regression. AF was modeled as a time-dependent variable to evaluate associations with clinical outcomes. RESULTS: – Among 3117 genotyped patients with DCM (mean age, 48±15 years; 39% were female; and 35% were G[+]), 12.3% (n=384) had prevalent AF. Of 2491 patients without prevalent AF and with follow-up, 312 (12.5%) developed AF during a median of 4.5 years (interquartile range, 1.6–9.0).